As highlighted by recent terrorist attacks on major cities, the public switched telephone network and cellular networks are vulnerable to significant service disruptions and discontinuities when large-scale disasters destroy key facilities. In contrast, Internet-based communications leverage the failure-resistant architecture of the Internet, thereby achieving higher reliability and survivability under adverse conditions.
Numerous products enable end users to communicate with others using voice over internet protocol (VOIP) technology. While these products serve various consumer and internet commerce functions, none are engineered to provide features needed for enterprises to provide continuity of operations in emergency situations. These features include means for dynamically creating or updating an authoritative index of members of the enterprise (e.g., employees) reachable using backup telecommunications systems, methods for routing calls from the public switched telephone network (PSTN) to these members, methods for routing calls within the enterprise to these members, and methods for enabling outside parties to reach these members using either Internet-connected computing devices or portions of the PSTN that are in working order.